Walk-Behind Sweeper

ABSTRACT

A walk-behind sweeper has at least one sweeping roller and an air-cooled drive motor having a drive shaft and driving in rotation the at least one sweeping roller. At least one fan wheel conveys cooling air to the drive motor wherein the at least one fan wheel is driven by the drive shaft. A dirt collecting chamber is provided into which swept-up material that is swept up by the at least one sweeping roller is conveyed. The at least one fan wheel has an intake side connected by a flow connection to a working area of the sweeper so that at least a portion of the cooling air stream for the drive motor is taken in from the working area of the sweeper.

BACKGROUND OF THE INVENTION

The invention relates to a walk-behind sweeper.

German patent application 195 31 327 A1 discloses a sweeper comprising a brush roller and a disk brush. The disk brush is driven by a drive unit. The sweeper has also a vacuum device with a motor which vacuum device removes air from a dirt collecting container. Because of the two motors for the disk brush and the vacuum device, the sweeper is comparatively heavy and has a complex configuration.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a sweeper that is of a simple configuration and has minimal weight.

In accordance with the present invention, this is achieved in that the sweeper has at least one sweeping roller and an air-cooled drive motor for rotatingly driving the sweeping roller, wherein the drive motor has a drive shaft that drives at least one fan wheel for conveying cooling air for the drive motor, wherein the sweeper has a dirt collecting chamber into which the swept-up material is conveyed by the sweeping roller and wherein the vacuum side of the fan wheel is connected to the working area of the sweeper so that at least one part of the cooling air stream for the drive motor is taken in from the working area of the sweeper.

By providing that at least one part of the cooling air stream for the drive motor is taken in from the working area of the sweeper, dust control of the sweeper is improved. Since the drive motor must convey a cooling air stream in any case, no additional means or drive devices are required. The already present fan wheel is simply used for reducing dust development (improving dust control). The sweeper has in this way a simple configuration and a minimal weight.

Advantageously, the fan wheel is connected by means of the dirt collecting chamber to the working area of the sweeper. In this way, a compact configuration of the drive motor and of the dirt collecting chamber is achieved. The cooling air stream enhances the conveying action of the swept-up material into the dirt collecting chamber. In order to avoid an excessive soiling of the drive motor and to prevent the swept-up material from escaping from the drive motor into the surroundings, it is provided that a filter is arranged in the flow connection connecting the working area to the vacuum side of the fan wheel. In particular, the filter is arranged at the exit of the cooling air from the dirt collecting chamber. The filter is arranged in this connection on the topside of the dirt collecting chamber so that the swept-up material that is retained by the filter will fall because of gravity back into the dirt collecting chamber. In this way, the cleaning expenditure for the filter is reduced.

Expediently, the vacuum side of the fan wheel is connected by a cooling air passage to the dirt collecting chamber. It is provided that the drive motor is arranged in the motor housing. The cooling air passage is embodied in particular in a connecting socket that connects the dirt collecting chamber to the motor housing. The connecting socket provides a mechanical connection between the motor housing and the dirt collecting chamber as well as a flow connection. The dirt collecting chamber is in particular provided in a dirt collecting container wherein the dirt collecting container is advantageously secured in a detachable way to the sweeper. In this way, the dirt collecting container can be emptied and cleaned in a simple way. It can also be provided that the cooling air passage is formed on the dirt collecting container. The cooling air passage and the dirt collecting container are formed in particular as a unitary part so that no additional components are required for the cooling air passage. In this way, the manufacture of the sweeper is simplified. Advantageously, the drive motor is arranged above the dirt collecting container. However, it can also be provided that the drive motor is arranged behind the dirt collecting container relative to the travel direction. In this way, a low constructive height of the sweeper can be achieved that enables sweeping even underneath obstacles.

Advantageously, the sweeper has two sweeping rollers that are driven by the drive motor in opposite directions and, relative to the ground, are driven toward one another. The sweeping rollers convey the swept-up material expediently in accordance with the overthrow principle into the dirt collecting chamber. It has been found that the conveying action of the swept-up material in accordance with the overthrow principle provides an excellent cleaning result. It is possible to take up small dust particles as well as coarse debris such as boxes, cartons, packets, cans or the like.

In order to achieve an excellent dust control, it can be provided that the entire cooling air stream for the drive motor is taken in from the working area of the sweeper. However, it can also be provided that the portion of the cooling air stream taken in from the working area of the sweeper is adjustable. In this way, the intake of cooling air can be variably adjusted by the operator in regard to the requirements on site.

Advantageously, the drive motor is an internal combustion engine and the crankshaft of the internal combustion engine is the drive shaft for the fan wheel. The internal combustion engine has in particular a cylinder that has cooling ribs. The fan wheel is advantageously provided for conveying the cooling air to the cooling ribs of the cylinder of the internal combustion engine. Especially in the case of an internal combustion engine it is necessary to convey cooling air to the engine. The fan wheel is present in an internal combustion engine in any case so that no additional components are required.

However, it can also be provided that the drive motor is an electric motor having a battery for supplying energy. In this case, the battery is in particular a rechargeable battery. Advantageously, it is provided that the battery is arranged in the cooling air stream conveyed by the fan wheel. The capacity of the battery, in particular of a rechargeable battery, is significantly higher at low temperature than at high temperature. By cooling the battery, a significantly increased performance can be provided. In that the battery is arranged within the cooling air stream that is conveyed by the fan wheel in any case, it is not necessary to provide additional devices for cooling the battery. It can also be advantageous that only the battery is arranged in the cooling air stream while the electric motor is not being cooled.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a schematic side view of a walk-behind sweeper.

FIG. 2 is a schematic section illustration of the walk-behind sweeper of FIG. 1.

FIG. 3 is a schematic side view of one embodiment of the sweeper.

FIG. 4 is a schematic side view of another embodiment of the sweeper.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The sweeper 1 illustrated in FIG. 1 has a handle frame 2 on which two handles 3 are attached. By means of the handles 3, the sweeper 1 can be moved across the floor by the operator. The sweeper 1 has two front wheels 4 and two rear wheels 5 of which only one is illustrated, respectively, in FIG. 1. The two front wheels 4 and the two rear wheels 5 are not powered. The sweeper 1 has a leading sweeping roller 6 that, relative to the travel direction 48 of the sweeper 1, is arranged in front of the two front wheels 4; also provided is a rear sweeping roller 7 that, relative to the travel direction 48, is arranged between the front wheels 4 and the rear wheels 5. The sweeper 1 has a dirt collecting container 8. Above the rear sweeping roller 7 there is a baffle or deflector 9 that deflects the swept-up material that has been swept up by the sweeping rollers 6, 7 to the dirt collecting container 8. The swept-up material is conveyed into a dirt collecting chamber 50 that is provided in the dirt collecting container 8. A motor housing 10 is arranged behind the dirt collecting container 8 relative to the travel direction 48. The motor housing 10 has exit openings 18 for cooling air.

FIG. 2 shows a schematic section illustration of the sweeper 1. As shown in FIG. 2, a drive motor configured as an internal combustion engine 11 is arranged in the motor housing 10. The internal combustion engine 11 has a cylinder 21 provided with cooling ribs 12 on its exterior. The internal combustion engine 11 is an air-cooled single cylinder motor, particularly a two-stroke engine. The internal combustion chamber 11 drives the crankshaft 14 in rotation. Fixedly connected to the crankshaft 14 is a fan wheel 13 that conveys cooling air to the cylinder 21. The cooling air flows in the direction of arrows 25 across the cooling ribs 12 of the cylinder 21. The fan wheel 13 has a vacuum side 15 where, as a result of the rotation of the fan wheel 13, a vacuum is generated. Advantageously, the fan wheel 13 takes in the cooling air stream in the axial direction of the crankshaft 14 and conveys the cooling air in the radial direction outwardly. At the vacuum side 15, the fan wheel 13 takes in the cooling air in the direction of arrow 24.

The vacuum side 15 of the fan wheel 13 is connected by a cooling air passage 22 to the clean side 23 of the filter 16. The filter 16 is arranged at the topside 45 of the dirt collecting chamber 50. The filter 16 is arranged in a filter housing 19; the filter housing 19 and the dirt collecting container 8 are configured as a monolithic or unitary part. The filter housing 19 is dosed by a cover 49. The filter 16 is accessible for maintenance work through cover 49. The motor housing 10 has an intake opening 36 through which additional cooling air from the surroundings is taken in. At the intake opening 36 a slide 37 is arranged that is movable in the direction of arrow 38. By means of the slide 37, the open cross-sectional area of the intake opening 36 and thus the portion of cooling air stream taken in from the surroundings are adjustable. It can also be provided that means for adjusting the cooling air stream taken in from the working area are arranged on the cooling air passage 22. The intake opening 36 is schematically illustrated in FIG. 2. Instead of slide 37, other means for changing the open cross-sectional area are possible. The intake opening 36 can advantageously be arranged laterally or on the topside of the motor housing 10 facing the operator.

The crankshaft 14 drives by means of gear 28 the front sweeping roller 6 and the rear sweeping roller 7 in opposite directions. The front or leading sweeping roller 6 is driven in a rotational direction 26 that, relative to the floor, is opposite to the travel direction 48. The rear sweeping roller 7 is driven in a rotational direction 27 that is opposite to the rotational direction 26 and, on the floor, is oriented in the travel direction 48. It can be provided that only one of the sweeping rollers 6, 7 is driven by the gear 28 and the movement of the other sweeping roller 7, 6 is coupled, for example, by means of a belt drive or the like to the driven sweeping roller. In this way, the internal combustion engine 11 drives in rotation both sweeping rollers 6, 7.

The two sweeping rollers 6, 7 convey the swept-up material into the interstice formed between the two sweeping rollers 6, 7 and upwardly. The swept-up material is conveyed in accordance with the overthrow principle, whose conveying action is indicated by arrow 20, into the dirt collecting chamber 50. The swept-up material is guided by the deflector 9 into the dirt collecting chamber 50.

As shown in FIG. 1, in the travel direction 48 between the two sweeping rollers 6 and 7 a working area 17 of the sweeper 1 is provided from where the sweeping rollers 6, 7 convey the swept-up material. From the working area 17 of the sweeper 1, the cooling air for the internal combustion engine 11 is taken in by the fan wheel 13 through the cooling air passage 22, the filter 19, and the dirt collecting chamber 50. In this way, the dust control during sweeping is improved. Conveying of the swept-up material into the dirt collecting chamber 50 is assisted by the cooling air stream. The cooling air passage 22 is formed in the dirt collecting container 8. The cooling air passage 22 and the dirt collecting container 8 are formed as a unitary part. In this way, no additional components are required for providing the flow connection of the working area 17 to the intake side 15 of the fan wheel 13.

One embodiment of the sweeper 30 is illustrated in FIG. 3. The configuration of the sweeper 30 corresponds essentially to that of the sweeper 1. Identical components are referenced by the same reference numerals in the drawings.

The internal combustion engine 11 of the sweeper 30 is arranged above the dirt collecting container 8 in the motor housing 40. The motor housing 40 can be supported on a frame 39 of the sweeper 30. The motor housing 40 is connected by connecting socket 31 to the working area 17 of the sweeper 30. The flow connection is realized by the dirt collecting chamber that is provided in the dirt collecting container 8. The filter 16 is arranged at the exit of the dirt collecting container 8 where the cooling air stream that is taken by the fan wheel 13 in the direction of arrow 34 exits from the container 8. The filter 16 is arranged on the topside 45 of the dirt collecting chamber 50.

A cooling air passage 32 for the conveyed cooling air is formed within the connecting socket 31 through which the entire cooling air is taken in. However, means for adjusting the cooling air portion that is taken in from the working area by means of the connecting socket 31 can be provided. An additional intake opening for taking in cooling air from the surroundings can be provided. The connecting socket 31 provides a mechanical connection between the motor housing 40 and the dirt collecting container as well as a flow connection between the intake side 15 of the fan wheel 13 and the dirt collecting chamber 50. The fan wheel 13 conveys the cooling air, taken in as indicated by arrows 34, across the cooling ribs 12 of the internal combustion engine 11 in the direction of arrow 35. The cooling air stream can exit the motor housing 40 through exit openings 18.

FIG. 4 shows another embodiment of the sweeper 46. The sweeper 46 corresponds essentially to the sweeper 1 of FIGS. 1 and 2. Identical reference numerals identify identical components. As a drive motor, the sweeper 46 has an electric motor 41 whose drive shaft 44 drives the fan wheel 13 and the sweeping rollers 6 and 7. The electric motor 41 is arranged in the cooling air stream that is conveyed by the fan wheel 13 and illustrated by arrows 24 and 25. The energy supply for the electric motor 41 is provided by battery 42 that is configured as a rechargeable battery. The battery 42 is also arranged in the cooling air stream conveyed by the fan wheel 13 so that the electric motor 41 as well as the battery 42 in operation of the sweeper are cooled by the cooling air stream. In order to enable in a simple way recharging of the battery 42, a connector 43 is provided that is accessible from the exterior of the motor housing 10 and is connected to the battery 42. It can also be provided that the battery 42 is removed from the housing 10 for recharging.

The specification incorporates by reference the entire disclosure of German priority document 10 2006 037 452.5 having a filing date of 10 Aug. 2006.

While specific embodiments of the invention have been shown and described in detail to illustrate the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles. 

What is claimed is:
 1. A walk-behind sweeper comprising: at least one sweeping roller; an air-cooled drive motor having a drive shaft and driving in rotation the at least one sweeping roller; at least one fan wheel for conveying cooling air to the drive motor wherein the at least one fan wheel is driven by the drive shaft; a dirt collecting chamber into which swept-up material that is swept up by the at least one sweeping roller is conveyed; wherein the at least one fan wheel has an intake side connected by a flow connection to a working area of the sweeper so that at least a portion of the cooling air for the drive motor is taken in from the working area of the sweeper.
 2. The sweeper according to claim 1, wherein the intake side of the at least one fan wheel is connected via the dirt collecting chamber to the working area of the sweeper.
 3. The sweeper according to claim 1, comprising a filter arranged in the flow connection between the working area and the intake side of the at least one fan wheel.
 4. The sweeper according to claim 3, wherein the filter is arranged at an exit of the dirt collecting chamber from which exit the cooling air leaves the dirt collecting chamber.
 5. The sweeper according to claim 1, wherein the flow connection comprises a cooling air passage, wherein the intake side of the at least one fan wheel is connected by the cooling air passage to the dirt collecting chamber.
 6. The sweeper according to claim 1, comprising a motor housing in which motor housing the drive motor is arranged.
 7. The sweeper according to claim 6, further comprising a connecting socket connecting the dirt collecting chamber to the motor housing, wherein the flow connection comprises a cooling air passage and the cooling air passage is provided in the connecting socket.
 8. The sweeper according to claim 1, comprising a dirt collecting container in which the dirt collecting chamber is provided.
 9. The sweeper according to claim 8, wherein the dirt collecting container is detachably secured on the sweeper.
 10. The sweeper according to claim 8, wherein the flow connection comprises a cooling air passage and the cooling air passage is provided on the dirt collecting container.
 11. The sweeper according to claim 8, wherein the drive motor is arranged above the dirt collecting container.
 12. The sweeper according to claim 8, wherein the drive motor is arranged behind the dirt collecting container in a travel direction of the sweeper.
 13. The sweeper according to claim 1, wherein the sweeper has two of said at least one sweeping roller, wherein said two sweeping rollers are driven in opposite directions and, relative to a ground on which the sweeper travels, are driven toward one another.
 14. The sweeper according to claim 13, wherein said two sweeping rollers convey the swept-up material according to an overthrow principle into the dirt collecting chamber.
 15. The sweeper according to claim 1, wherein the cooling air for the drive motor is completely taken in from the working area of the sweeper.
 16. The sweeper according to claim 1, wherein an amount of the cooling air taken in from the working area of the sweeper is adjustable.
 17. The sweeper according to claim 1, wherein the drive motor is an internal combustion engine, wherein the drive shaft is a crankshaft of the internal combustion engine, and wherein the internal combustion engine has a cylinder with cooling ribs, wherein the at least one fan wheel is provided for conveying cooling air to the cooling ribs of the cylinder of the internal combustion engine.
 18. The sweeper according to claim 1, wherein the drive motor is an electric motor comprising a battery supplying energy.
 19. The sweeper according to claim 18, wherein the battery is arranged in the cooling air conveyed by the at least one fan wheel. 